Adapter assemblies for surgical devices

ABSTRACT

An adapter assembly includes a base member, a housing, and a locking mechanism. The base member defines a longitudinal axis. The housing is rotatably secured to the base member and is rotatable in relation to the base member between a plurality of positions. The locking mechanism is supported on the housing and includes a locking member and a button. The locking member is moveable from a locked position in which a lock of the locking member is engaged with the base member to secure the housing in one of the plurality of positions to an unlocked position in which the housing is rotatable in relation to the base member. The button is positioned on the base member and is depressible to translate the locking member in a direction parallel to the longitudinal axis from the locked position to the unlocked position.

BACKGROUND 1. Technical Field

The present disclosure relates generally to adapter assemblies for selectively connecting end effectors to actuation units of surgical devices. More specifically, the present disclosure relates to adapter assemblies having a locking mechanism for rotationally securing a housing to a base.

2. Background of Related Art

Powered devices for use in surgical procedures typically convert rotational motion from an actuation assembly to linear motion for effectuating one or more functions, e.g., clamping, stapling, cutting. To permit rotational alignment of an end effector attached to the actuation assembly without the operator having to manipulate the actuation assembly in an uncomfortable or awkward position, adapter assemblies have been developed for enabling selective rotation of the end effector relative to the actuation assembly. Such adapter assemblies generally include a base that is fixedly secured to the actuation assembly and a body to which an end effector is attached that is rotatable relative to the base and the actuation assembly.

It would be beneficial to provide a surgical device including an adapter assembly with a locking mechanism that facilitates selective rotation of the body relative to the base but resists rotating forces that a clinician may exert on the body during use to prevent inadvertent rotation of the body relative to the base.

SUMMARY

This disclosure relates generally to adapter assemblies including a base member, a housing, and a locking mechanism for selectively securing the housing in a plurality of radial positions relative to the base member. The base member is securable to an actuation handle for actuating a tool assembly supported by the adapter assembly. The rotation of the housing affects the position of the end effector relative to the actuation handle.

In an aspect of the present disclosure, an adapter assembly includes a base member, a housing, and a locking mechanism. The base member defines a longitudinal axis of the adapter assembly. The housing is rotatably secured to the base member and is rotatable in relation to the base member between a plurality of positions. The locking mechanism is supported on the housing and includes a locking member and a button. The locking member is moveable from a locked position in which a lock of the locking member is engaged with the base member to secure the housing in one of the plurality of positions to an unlocked position in which the housing is rotatable in relation to the base member. The button is positioned on the base member and is depressible to translate the locking member in a direction parallel to the longitudinal axis from the locked position to the unlocked position.

In aspects, the locking member has a boss and the button defines a cam slot that receives the boss. The button may have an undepressed position in which the boss is positioned adjacent a first end of the cam slot and a depressed position in which the boss is positioned adjacent a second end of the cam slot. Walls defining the cam slot can engage the boss as the button is moved towards the depressed position to translate the locking member in the direction parallel to the longitudinal axis as the boss moves towards the second end of the cam slot. The adapter assembly may include a biasing member disposed between the button and the locking member that urges the button towards the undepressed position.

In some aspects, the base member includes an annular flange that defines first and second cutouts. The locking member may have a lock body, a distal leg, and a proximal leg. The distal and proximal legs may define a gap therebetween. In the unlocked position of the locking member, the annular flange may be rotatable within the gap. The lock of the locking member may extend proximally from the distal leg and be disposable within one of the first or second cutouts to secure the housing in one of the plurality of positions. The annular flange may define a third cutout that is diametrically opposed to the first cutout with the second cutout positioned between the first and third cutouts. The second cutout may be equidistant from the first and third cutouts.

In certain aspects, the housing defines a channel and the button is disposed within the channel.

In particular aspects, the adapter assembly includes a coupling body that extends from the housing and is rotatably fixed to the housing. The coupling body may have a proximal portion that includes a tab. The housing may define a recess that receives the tab to rotatably fix the coupling body to the housing.

In another aspect of the present disclosure, a surgical device includes a handle, a tool assembly, and an adapter assembly. The adapter assembly interconnects the handle and the tool assembly. The adapter assembly includes a base member, a housing, and a locking mechanism. The base member defines a longitudinal axis and the housing is rotatably secured to the base member. The housing is rotatable in relation to the base member between a plurality of positions such that rotation of the housing affects a position of the tool assembly relative to the handle. The locking mechanism is supported on the housing and includes a locking member and a button. In a locked position of the locking member, a lock of the locking member is engaged with the base member to secure the housing in one of the plurality of positions. In an unlocked position the housing is rotatable in relation to the base member. The button is positioned on the base member and is depressible to translate the locking member in a direction parallel to the longitudinal axis from the locked position to the unlocked position.

In aspects, the surgical device includes an extension assembly that includes a shaft having first and second ends. The first end of the shaft may be releasably coupled to a distal end of the adapter assembly and the second end of the shaft may support the tool assembly. The shaft may be curved between the first and second ends.

In some aspects, the adapter assembly includes a coupling body that extends from the base member. The coupling body may be rotatably fixed to the housing.

In certain aspects, the adapter assembly includes a coupling assembly that extends proximally from the base member and is releasably secured to the handle. The adapter assembly may include a drive assembly that extends through the coupling assembly, the base member, and the housing. The handle may engage the drive assembly to actuate the tool assembly. The drive assembly may include first and second connectors that are disposed within the coupling assembly. The first connector may be offset form the longitudinal axis.

In another aspect of the present disclosure, a method of reposition a tool assembly supported by an adapter is disclosed. The adapter defines a longitudinal axis and is coupled to a handle that is configured to actuate the tool assembly. The method includes depressing a button of the adapter, rotating the handle relative to the housing, and releasing the button. Depressing the button translates a locking member in a direction parallel to the longitudinal axis from a locked position, in which the handle is rotatably fixed relative to a housing of the adapter in a first position, to an unlocked position. Rotating the handle relative to the housing includes rotating a base member of the adapter within the housing with the locking member in the unlocked position such that the tool assembly is repositioned about relative to the handle. Releasing the button allows the locking member to return to the locked position with the housing rotatably fixed to the handle in a second position different from the first position.

In aspects, depressing the button of the adapter includes walls defining a cam slot of the button engaging a boss of the locking member to translate the locking member towards the unlocked position.

In some aspects, the method includes rotating the handle to the second position after releasing the button. Rotating the handle to the second position may include the locking member transitioning to the locked position when the handle reaches the second position. The locking member may provide feedback with the handle reaches the second position.

Further, to the extent consistent, any of the aspects described herein may be used in conjunction with any or all of the other aspects described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the present disclosure are described hereinbelow with reference to the drawings, which are incorporated in and constitute a part of this specification, wherein:

FIG. 1 is a side, perspective view of a surgical device including an exemplary embodiment of an adapter assembly provided in accordance with the present disclosure;

FIG. 2 is an enlarged, perspective, cutaway view of a proximal portion of the adapter assembly of FIG. 1;

FIG. 3 is a cross-sectional view taken along section line 3-3 of FIG. 2;

FIG. 4 is a perspective, exploded view of a locking mechanism and a base member of the adapter assembly of FIG. 3;

FIG. 5 is a front perspective view of the base member of FIG. 4;

FIG. 6 is a side, perspective view from the proximal end of the base member of FIG. 4;

FIG. 7 is a top perspective view of a locking member of the locking mechanism of FIG. 4;

FIG. 8 is a bottom perspective view of the locking member of the locking mechanism of FIG. 4;

FIG. 9 is a bottom perspective view of a button of the locking mechanism of FIG. 4;

FIG. 10 is a top perspective view of the button of the locking mechanism of FIG. 4;

FIG. 11 is a side view of the proximal portion of the adapter assembly shown in FIG. 2 with a housing of the adapter assembly removed and the locking mechanism in a locked position;

FIG. 12 is a cross-sectional view taken along section line 12-12 of FIG. 3;

FIG. 13 is a side view of the proximal portion of the adapter assembly with a housing of the adapter assembly removed and the locking mechanism in an unlocked position;

FIG. 14 is a side cross-sectional view of the proximal portion of the adapter assembly of FIG. 13;

FIG. 15 is a cross-sectional view taken along section line 15-15 of FIG. 3;

FIG. 16 is a cross-sectional view taken along section line 16-16 of FIG. 15;

FIG. 17 is a perspective view of the base member and the body of the adapter assembly shown in FIG. 1 in a first radial position relative to one another; and

FIG. 18 is a perspective view of the base member and the body of the adapter assembly shown in FIG. 17 in a second radial position relative to one another.

DETAILED DESCRIPTION OF EMBODIMENTS

This disclosure relates generally to adapter assemblies that include a base member, a housing, and a locking mechanism for selectively securing the housing in a plurality of radial positions about the base member. The base member can be selectively coupled to an actuation assembly such that the base member is rotatably fixed to the actuation assembly. The housing is rotatable about the base member such that a tool assembly supported by the housing of the adapter assembly is repositionable relative to the actuation assembly. The locking mechanism is provided to selectively lock the orientation of the housing relative to the base member and includes a locking member and a button. In embodiments, the locking member is slidable in a direction parallel to a longitudinal axis defined by the adapter assembly between a locked position and an unlocked position. The button may define a cam slot that receives a boss of the locking member such that walls defining the cam slot engage the boss to translate the locking member between the locked and unlocked positions.

Embodiments of the presently disclosed adapter assembly are now described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein, the term “clinician” refers to a doctor, a nurse, or any other care provider and may include support personnel. Throughout this description, the term “proximal” refers to the portion of the device or component thereof that is closest to the clinician and the term “distal” refers to the portion of the device or component thereof that is farthest from the clinician.

Referring to FIGS. 1 and 2, a surgical device 1 including an exemplary adapter assembly 10 is provided in accordance with the present disclosure. As shown, the adapter assembly 10 is releasably coupled to an actuation assembly 300 in the form of a powered handle. The actuation assembly 300 includes a coupler 310 and actuation controls 320. The actuation controls 320 are operable to selectively activate motors (not explicitly shown) that rotate drive shafts 84 a-c (FIG. 15) to actuate functions of an end effector or tool assembly 380 (e.g., drawing an anvil 392 towards a loading unit 390, firing staples from the loading unit 390, extending a knife from the loading unit 390, etc.). For a detailed description of the structure and function of an exemplary powered handle, please refer to U.S. Pat. No. 9,055,943 (“the '943 patent”), the entire contents of which are incorporated herein by reference. It is contemplated that the adapter assembly 10 can be configured for selective connection to a manually actuated actuation assembly such as described in U.S. Pat. No. 8,789,737, the entire contents of which are incorporated herein by reference.

The adapter assembly 10 includes a proximal end portion or base 20 that is releasably received by the coupler 310. An elongate coupling body 70 extends distally from the base 20 and has a distal end 90 configured for releasable connection with an extension assembly 290. The extension assembly 290 has a distal portion configured for releasable connection with the tool assembly 380. In exemplary embodiments, the tool assembly 380 includes a loading unit 390 and an anvil 392 for applying a circular array of staples (not shown) to tissue (not shown).

Alternatively, the elongate coupling body 70 and the extension assembly 290 can be integrally formed. In embodiments, the extension assembly 290, and/or the elongate coupling body 70, includes a shaft 292 that extends from the distal end 90 of the adapter assembly 10 to the tool assembly 380. As shown, the shaft 292 has a first end 292 a and a second end 292 b and a curved central section between the first and second ends 292 a, 292 b; however, it is contemplated that the shaft 292 can be substantially linear or have any suitable configuration between the first and second ends 292 a, 292 b. For a detailed description of an exemplary extension assembly and tool assembly reference can be made to the '943 patent.

Although aspects of the present disclosure will be shown and described as relates to the adapter assembly 10, it is envisioned that the aspects of the present disclosure may be adapted for use with adapter assemblies having an alternative configuration. For a detailed description of exemplary adapter assemblies and exemplary extension assemblies reference can be made to commonly owned U.S. patent application Ser. No. 14/875,766 (“the '766 application”), filed Oct. 6, 2015, the content of which is incorporated by reference herein in its entirety.

With reference to FIGS. 2 and 3, the adapter assembly 10 includes the base 20 and a rotation assembly 40. The base 20 includes a coupling assembly 22 and a base member 50. The base 20 defines a longitudinal axis X-X (FIG. 3) of the adapter assembly 10. The rotation assembly 40 includes a housing 42 that is rotatably supported about the base 20 and an elongate coupling body 70 that extends distally from the housing 42. The adapter assembly 10 also includes a drive assembly 80 (FIG. 3) that extends through the coupling assembly 22, the housing 42, and the elongate coupling body 70 to transfer power from the coupler 310 (FIG. 1) of the actuation assembly 300 to the tool assembly 380 (FIG. 1). The coupling assembly 22 is configured to releasably secure the adapter assembly 10 to the coupler 310 of the actuation assembly 300 (FIG. 1).

Briefly, the drive assembly 80 of the adapter assembly 10 includes first, second, and third connectors 82 a, 82 b, 82 c (FIG. 2) configured for operable connection with first, second, and third drive shafts (not shown) of the actuation assembly 300. As shown in FIG. 3, the second connector 82 b is operably connected to an elongate drive shaft 84 b of the drive assembly 80 for transferring rotational motion from the actuation assembly 300 through the adapter assembly 10. Each of the first and third connectors 82 a, 82 c are operably connected to planetary gear assemblies 86 (FIG. 16) supported within the adapter assembly 10. The planetary gear assemblies 86 are configured to convert the rotational motion from the drive shafts of the actuation assembly 300 to longitudinal motion of the drive shafts 84 a-c to facilitate operation of the tool assembly 380. For a detailed description of exemplary adapter assemblies, including an exemplary coupling assembly and exemplary drive assemblies, please refer to the '766 application, the content of which was previously incorporated by reference herein.

With reference to FIGS. 2-4, the rotation assembly 40 of the adapter assembly 10 includes the housing 42 that is rotatably supported on the base member 50 and a locking mechanism 60 disposed within the housing 42. The housing 42 supports the elongate coupling body 70. As will be described in further detail below, the locking mechanism 60 has a locked position (FIG. 3) in which the housing 42 is rotationally secured relative to the base member 50 and an unlocked position (FIG. 13) in which the housing 42 is rotatable about the longitudinal axis X-X in relation to the base member 50. As described in further detail below, the tool assembly 380 is rotatably fixed to a distal portion of the extension assembly 290 which is rotatably fixed to the distal portion of the elongate coupling body 70. As such, rotation of the housing 42 about the longitudinal axis X-X of the adapter assembly 10 causes the tool assembly 380 (FIG. 1), which defines a longitudinal axis Y-Y (FIG. 1), to rotate about the longitudinal axis X-X of the adapter assembly 10 to facilitate repositioning of the tool assembly 380 relative to the actuation assembly 300. This enables a clinician to orient the tool assembly 380 relative to the actuation assembly 300 without changing the orientation of the actuation assembly 300.

The housing 42 may be formed from a first body shell 44 and a second body shell 46. Each of the first and second body shells 44, 46 form approximately half of the housing 42 and are joined together by fasteners 47. Alternatively, the first and second body shells 44 and 46 may be secured together by welding or the like. Each of the first and second body shells 44, 46 define a recess 48 (FIG. 3) that extends about the elongate coupling body 70. The elongate coupling body 70 has an outer surface that includes tabs 72 that are received within a respective one of the recesses 48 to rotatably fix the elongate coupling body 70 to the housing 42.

Referring to FIGS. 4 and 5, the base member 50 includes a substantially cylindrical member 120 defining longitudinal openings 122 a, 122 b, 122 c that are configured to receive the drive assembly 80 (FIG. 3). The base member 50 also includes proximal and distal annular flanges 124, 126 and further defines proximal and distal annular grooves 125, 127. The proximal annular flange 124 facilitates attachment of the base member 50 to the coupling assembly 22. The proximal annular groove 125 accommodates an annular retention flange 49 (FIG. 3) of the housing 42 to longitudinally secure the housing 42 relative to the base member 50 while allowing the housing 42 to rotate about the base member 50.

With reference to FIGS. 4-6, the distal annular flange 126 and the distal annular groove 127 of the base member 50 operate in combination with the locking mechanism 60 to secure the housing 42 in fixed rotational orientation relative to the base member 50. In particular, the distal annular flange 126 of the base member 50 defines a plurality of lock cutouts, e.g., first, second, and third lock cutouts 152 a-c, that are configured to receive a lock 156 of the locking mechanism 60 as described in greater detail below to retain the housing 42 in one of a plurality of fixed positions in relation to the base member 50. As shown the first and third lock cutouts 152 a, 152 c are diametrically opposed to one another and the second lock cutout 152 b oriented halfway between the first and third lock cutouts 152 a, 152 c. It is envisioned that the distal annular flange 126 may define any number of lock cutouts which may be arranged in any suitable configuration. For example, the lock cutouts may be arranged in set intervals, uniformly or randomly spaced, and, where the drive assembly 80 permits, the lock cutouts may be formed to extend entirely around the distal annular flange 126 to permit locking of the housing 42 in any three-hundred sixty degree (360°) orientation about the base member 50.

Referring now to FIGS. 4 and 7-10, in embodiments, the locking mechanism 60 includes the locking member 150, a button 160, and biasing members 179. With particular reference to FIGS. 7 and 8, the locking member 150 includes a body 153, a distal leg 154, and a proximal leg 158. The body 153 defines a body axis B-B that passes through the distal and proximal legs 154, 158. The body 153 includes a finger 153 a that extends over the distal leg 154 and bosses 157 that extend from the body 153 in a direction orthogonal to the body axis B-B. The distal leg 154 includes a stop 155 and a lock 156. The stop 155 forms a T-shape with the distal leg 154 and has a width greater than the width of the lock cutouts 152 a-c such that the stop 155 prevents the distal leg 154 from passing entirely through the lock cutouts 152 a-c. The lock 156 is sized and dimensioned to be positioned within a respective one of the lock cutouts 152 a-c when the locking member 150 is in a locked position to prevent rotation of the housing 42 relative to the base member 50. The lock 156 extends proximally from the distal leg 154 and is configured such that when the lock 156 is positioned in a respective one of the lock cutouts 152 a-c, the stop 155 abuts the distal annular flange 126. The proximal leg 158 includes a foot 159 that is positioned within the distal annular groove 127 of the base member 50. The distal leg 154 and the proximal leg 158 define a gap 151 therebetween that is sized and dimensioned to allow the distal annular flange 126 to rotate within the gap 151 when the locking member 150 is in an unlocked position as shown in FIG. 13.

Referring now to FIGS. 9 and 10, the button 160 has a button body 161 that defines blind holes 162, an opening 163, and camming slots 164. The opening 163 extends inward from a bottom surface 161 a of the button body 161 to define a distal opening 163 a in a distal surface 161 b of the body 161. The distal opening 163 a includes a shelf 163 b opposite the bottom surface 161 a of the button body 161. The blind holes 162 extend substantially vertically from the bottom surface 161 a of the button body 161 on either side of the opening 163 in a direction orthogonal to a plane defined by the bottom surface 161 a. The blind holes 162 may be substantially cylindrical and are sized to receive the biasing members 179 (FIG. 4).

The camming slots 164 pass entirely through side surfaces 161 d of the button body 161. The camming slots 164 extend from a first end 164 a of the button body 161 adjacent the bottom surface 161 a of the button body 161 and a proximal surface 161 e of the button body 161 to a second end 164 b of the button body 161 adjacent the distal surface 161 b and a top surface 161 c of the button body 161 such that the cam slots 164 are inclined distally upward when the button 160 is viewed in profile. The camming slots 164 are in communication with the opening 163 and configured to receive the bosses 157 of the locking member 150 such that vertical movement of the button 160 (i.e., movement substantially towards and away from the longitudinal axis X-X as viewed in FIG. 11) affects longitudinal translation of the locking member 150 as described in detail below.

Referring to FIGS. 3, 11, and 12, the locking mechanism 60 is disposed in a channel 142 defined in the housing 42. The locking mechanism 60 is positioned on the base member 50 adjacent the distal annular flange 126. In a locked position of the locking mechanism 60, the lock 156 is disposed within one of the lock cutouts 152 a-c defined in the distal annular flange 126 to rotatably fix the orientation of the housing 42 relative to the base member 50. The button 160 is positioned radially outward of the locking member 150 such that the body 153 of the locking member 150 is disposed within the opening 163 of the button 160. When the body 153 is disposed within the opening 163, the bosses 157 of the locking member 150 are slidingly received within the cam slots 164. In addition, the biasing members 179 are received within the blind holes 162 to urge the button 160 away from the locking member 150. In this position, the locking member 150, due to engagement with the portion of the button 160 defining the cam slots 164, is urged proximally to the locked position.

With particular reference to FIG. 12, the biasing members 179 are supported on a ledge 144 of the body shell 44 to bias the button 160 away from the locking member 150. However, it is contemplated that the biasing members 179 may be supported by and be slidable along a top surface of the stop 155.

Briefly referring back to FIG. 3, the finger 153 a of the locking member 150 extends distally within the opening 163 of the button 160 such that the finger 153 a is positioned over the shelf 163 b of the button 160 to retain the button 160 within the channel 142 of the housing 42. In addition, the proximal surface 161 e (FIG. 9) of the button 160 can include a retention hook 166 that extends proximally from the proximal surface 161 e of the button 160 into engagement with the housing 42 to retain the button 160 within the channel 142.

Referring to FIG. 11, in the unlocked position of the locking mechanism 60, the button 160 is urged upwardly by the biasing members 179 such that the locking member 150 is cammed by the bosses 157 to a proximal position. In the proximal position, the lock 156 is positioned within a lock cutout 152 a-c of the flange 126 of the base member 50 to prevent rotation of the housing 42 in relation to the base member 50. Referring now to FIGS. 13 and 14, to move the lock mechanism 60 to the unlocked position, the button 160 is depressed within the channel 142 of the housing 42 against the bias members 179. As the button 160 is depressed, the button 160 is confined to substantially vertical movement (movement towards and away from the longitudinal axis X-X) within the channel 142 of the housing 42. As the button 160 is depressed, the bosses 157 slide within the cam slots 164 to affect distal longitudinal movement of the locking member 150 relative to the housing 42. Specifically, walls defining the cam slots 164 engage the bosses 157 to translate the locking member 150 in a direction substantially parallel to the longitudinal axis X-X. As the locking member 150 moves distally relative to the button 160, the lock 156 moves from within a cutout 152 a-c to a position distal of the distal annular flange 126, and thus out of the lock cutout 152 a-c. In this position, the housing 42 is free to rotate about the base member 50. As the locking member 150 moves distally, the foot 159 of the proximal leg 158 slides within the distal annular groove 127 and may abut the distal annular flange 126 to limit distal movement of the locking member 150. In embodiments, contact between the foot 159 of the locking member 150 with the distal annular flange 126 may provide tactile feedback to a clinician that the button 160 is fully depressed and/or that the locking mechanism 60 is in the unlocked position. In addition, when the button 160 is fully depressed, the body 153 of the locking member 150 may engage a roof 163 c of the opening 163 to limit depression of the button 160 and/or distal movement of the locking member 150.

With reference to FIGS. 15-18, with the locking mechanism 60 in the unlocked position, the housing 42 is rotatable about the base member 50, the coupling assembly 22, and the drive assembly 80. Rotation of the housing 42 also rotates the elongate coupling body 70 about the longitudinal axis X-X through the engagement of the tabs 72 (FIG. 14) with the housing 42.

With particular reference to FIGS. 17 and 18, when the housing 42 is rotated from a first radial position (FIG. 17) to a second radial position (FIG. 18), the extension assembly 290 is rotated with the distal end 90 of the elongate coupling body 70. The extension assembly 290 has a tool coupler 294 on a distal portion thereof that releasably secures the tool assembly 380 (FIG. 1) to the extension assembly 290. As shown, rotation of the housing 42 about the longitudinal axis X-X of the adapter assembly 10 changes the position of the tool coupler 294, and thus, the position of a tool assembly 380 secured to the tool coupler 294, relative to the coupling assembly 22. As the housing 42 is rotated, the drive assembly 80 maintains its position relative to the coupling assembly 22. It will be appreciated that when the coupling assembly 22 is secured to the actuation assembly 300 (FIG. 1), rotation of the housing 42 in relation to the actuation assembly 300 allows a clinician to reposition the tool assembly 380 (FIG. 1) without having to reposition the actuation assembly 300.

If the housing 42 is rotated relative to the base member 50 with the lock cutouts 152 a-c misaligned with the lock 156 and the button 160 is released, the lock 156 will abut the distal annular flange 126 until the lock 156 is aligned with one of the lock cutouts 152 a-c. When the lock 156 is aligned with one of the lock cutouts 152 a-c, the biasing members 179 will urge the button 160 away from the longitudinal axis X-X and affect proximal movement of the locking member 150 such that the lock 156 will slide into the aligned lock cutout 152 a-c. When the lock 156 slides into the aligned lock cutout 152 a-c, the slider 155 may contact the distal annular flange 126 to provide audible indicia (a “click”) that the housing 42 is rotationally secured to the base member 50.

While rotation of the housing 42 about the base member 50 is detailed above, it is contemplated that the base member 50 may be rotated within the housing 42 such that the actuation assembly 300 is repositionable relative to the tool assembly 380 while tool assembly 380 remains substantially stationary within a surgical site.

The rotation assembly can be incorporated into surgical instrument such as ultrasonic cutting instruments, surgical staplers, surgical clip appliers, and the like. In one example, the surgical instrument has a circular anvil and circular staple cartridge for applying circular rows of staples, as is known. Linear endoscopic staplers are another example. The rotation assembly can be incorporated into an elongate shaft of a manually operated or motorized surgical instrument. The elongate shaft can be integral with the handle or can be provided as an adapter that attaches to a handle, and also attaches to a loading unit. Furthermore, the rotation assembly can be incorporated into a device for use with a robotic surgical system.

Any of the components described herein may be fabricated from either metals, plastics, resins, composites or the like taking into consideration strength, durability, wearability, weight, resistance to corrosion, ease of manufacturing, cost of manufacturing, and the like.

While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Any combination of the above embodiments is also envisioned and is within the scope of the appended claims. The present disclosure is not limited to circular stapling loading units, but has application to loading units for linear stapling or other types of instruments, such as electrocautery or ultrasonic instruments. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope of the claims appended hereto. 

What is claimed is:
 1. An adapter assembly comprising: a base member defining a longitudinal axis; a housing rotatably secured to the base member, the housing rotatable in relation to the base member between a plurality of positions; and a locking mechanism supported on the housing, the locking mechanism including: a locking member moveable from a locked position in which a lock of the locking member is engaged with the base member to secure the housing in one of the plurality of positions to an unlocked position in which the housing is rotatable in relation to the base member; and a button positioned on the base member and depressible to translate the locking member in a direction parallel to the longitudinal axis from the locked position to the unlocked position.
 2. The adapter assembly according to claim 1, wherein the locking member has a boss, and wherein the button defines a cam slot that receives the boss.
 3. The adapter assembly according to claim 2, wherein the button has an undepressed position in which the boss is positioned adjacent a first end of the cam slot and a depressed position in which the boss is positioned adjacent a second end of the cam slot, and wherein walls defining the cam slot engage the boss as the button is moved towards the depressed position to translate the locking member in the direction parallel to the longitudinal axis as the boss moves towards the second end of the cam slot.
 4. The adapter assembly according to claim 3, further comprising a biasing member disposed between the button and the locking member, the biasing member urging the button towards the undepressed position.
 5. The adapter assembly according to claim 1, wherein the base member includes an annular flange defining a first cutout and a second cutout.
 6. The adapter assembly according to claim 5, wherein the locking member has a lock body, a distal leg, and a proximal leg, the distal and proximal legs defining a gap therebetween, the annular flange rotatable within the gap when the locking member is in the unlocked position.
 7. The adapter assembly according to claim 5, wherein the lock of the locking member extends proximally from the distal leg and is disposable within one of the first or second cutouts to secure the housing in one of the plurality of positions.
 8. The adapter assembly according to claim 5, wherein the annular flange defines a third cutout, the first and third cutouts diametrically opposing one another with the second cutout positioned between the first and third cutouts.
 9. The adapter assembly according to claim 8, wherein the second cutout is equidistant from the first and third cutouts.
 10. The adapter assembly according to claim 1, wherein the housing defines a channel, the button disposed within the channel.
 11. The adapter assembly according to claim 1, further comprising a coupling body extending from the housing, the coupling body rotatably fixed to the housing.
 12. The adapter assembly according to claim 11, wherein the coupling body has a proximal portion including a tab, and wherein the housing defines a recess that receives the tab to rotatably fix the coupling body to the housing.
 13. A surgical device comprising: a handle; a tool assembly; and an adapter assembly interconnecting the handle and the tool assembly, the adapter assembly including: a base member defining a longitudinal axis; a housing rotatably secured to the base member, the housing rotatable in relation to the base member between a plurality of positions, rotation of the housing affecting a position of the tool assembly relative to the handle; and a locking mechanism supported on the housing, the locking mechanism including: a locking member moveable from a locked position in which a lock of the locking member is engaged with the base member to secure the housing in one of the plurality of positions to an unlocked position in which the housing is rotatable in relation to the base member; and a button positioned on the base member and depressible to translate the locking member in a direction parallel to the longitudinal axis from the locked position to the unlocked position.
 14. The surgical device according to claim 13, further comprising an extension assembly including a shaft having a first end and a second end, the first end of the shaft releasably coupled to a distal end of the adapter assembly and the second end of the shaft supporting the tool assembly.
 15. The surgical device according to claim 14, wherein the shaft is curved between the first and second ends.
 16. The surgical device according to claim 13, wherein the adapter assembly includes a coupling body extending from the base member, the coupling body rotatably fixed to the housing.
 17. The surgical device according to claim 13, wherein the adapter assembly includes a coupling assembly extending proximally from the base member and releasably secured to the handle.
 18. The surgical device according to claim 17, wherein the adapter assembly includes a drive assembly that extends through the coupling assembly, the base member, and the housing, and wherein the handle engages the drive assembly to actuate the tool assembly.
 19. The surgical device according to claim 18, wherein the drive assembly includes a first connector and a second connector disposed within the coupling assembly, the first connector offset from the longitudinal axis.
 20. A locking mechanism for a rotatable surgical instrument, comprising: a base member, a button, and a locking member, the locking member having a body, a distal leg and a proximal leg, the body having an axis B-B extending through the distal leg and proximal leg, the body including bosses that extend in an orthogonal direction and being offset from the axis B-B, and further comprising a stop forming a T-shape with the distal leg, the distal leg defining a lock.
 21. The locking mechanism of claim 20, wherein the body includes a finger that extends over the distal leg.
 22. The locking mechanism of claim 20, wherein the proximal leg has a foot opposite the stop.
 23. The locking mechanism of claim 20, wherein the locking member is rotatable about the bosses.
 24. The locking mechanism of claim 22, wherein the base member has an annular groove, the foot being disposed in the annular groove.
 25. The locking mechanism of claim 24, wherein the base member has a plurality of lock cutouts for receiving the stop.
 26. The locking mechanism of claim 20, wherein the button has camming slots intersecting an opening, and a retention hook at a proximal end thereof, the bosses of the locking member being received in the camming slots.
 27. The locking mechanism of claim 26, wherein the button further comprising holes for receiving biasing members.
 28. The locking mechanism of claim 20, wherein vertical movement of the button effects translation of the locking member generally longitudinally.
 29. A rotatable surgical instrument having the locking mechanism of claim
 20. 30. The rotatable surgical instrument of claim 29, wherein the locking mechanism is part of the rotation assembly.
 31. The rotatable surgical instrument of claim 29, wherein the locking mechanism is part of an adapter assembly. 